High security fastener constructions

Abstract

A series of high security fastener constructions feature rotatable anti-theft shrouds mounted on locking wheel nuts and wheel bolts designed for vehicular wheels. Each construction features (1) a fastener body having a first body end adapted to accommodate a key receiving pattern or member, a second body end having thread pattern extending therefrom, and a shroud receiving portion located between the first and second body ends, (2) a shroud concentrically mounted on the shroud receiving, and (3) a shroud retaining system for retaining the shroud for rotation relative to the fastener body such that the shroud will rotate under an applied torque prior to the fastener rotating when it is installed at a design installation torque. Exemplary shroud retaining systems include (1) designs in which the shroud is retained by interference engagement of its inner side with the fastener body, (2) designs in which the shroud is retained by staking or swaging to the fastener body, and (3) designs in which the shroud is retained by first and second retaining members that are mounted on the fastener body in facing relationship with first and second annular faces of the shroud. The shroud can be substantially tubular, or it can be thickened at one end to provide a security enhancement feature.

1. A high security fastener, comprising:
 a fastener body; 
 a first body end on said fastener body; 
 a key-receiving pattern at said first body end; 
 a second body end on said fastener body; 
 a thread pattern extending from said second body end; 
 a shroud-receiving body portion on said fastener body extending from said first body end toward said second body ends; 
 an annular shroud-retaining shoulder defining an end of said shroud-receiving body portion that is remote from said first body end, said shroud-retaining shoulder facing toward said first body end; 
 a shroud concentrically mounted on said shroud-receiving portion, said shroud having a first shroud end terminating substantially at said first body end and a second shroud end terminating substantially at said shroud-retaining shoulder, said shroud having a thickened wall portion proximate to said first body end adapted to resist insertion of an unauthorized tool between said shroud and said body; 
 an annular end face at said shroud second end in opposing relationship with said annular shroud-retaining shoulder such that said shroud is restrained in a direction of movement toward said second body end; 
 an annular clearance groove in said shroud-receiving portion at said shroud second end; 
 a retainer retaining said shroud on said shroud-receiving portion, said retainer being disposed in opposing annular retainer grooves respectively formed in said shroud and said shroud-receiving portion at a location that is spaced from said first body end such that said shroud is restrained in a direction of movement toward said first body end; and 
 said shroud being supported in rotatable relationship with said shroud-receiving portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener rotating when said fastener is engaged with an external structure at a design installation torque. 
 
   
   
     2. A fastener in accordance with  claim 1  wherein said thickened wall portion is provided by a radial flange on said shroud. 
   
   
     3. A fastener in accordance with  claim 2  wherein said radial flange wraps around said first body end of said fastener body. 
   
   
     4. A fastener in accordance with  claim 2  wherein said radial flange wraps around said first body end of said fastener and is received in an annular groove. 
   
   
     5. A fastener in accordance with  claim 2  wherein said radial flange wraps around said first body end of said fastener and fully extends across a face of said first body end. 
   
   
     6. A fastener in accordance with  claim 2  wherein said radial flange wraps around said first body end of said fastener and partially extends across a face of said first body end. 
   
   
     7. A fastener in accordance with  claim 2  wherein said shroud is formed with a recess adjacent to said radial flange to prevent an unauthorized tool from squeezing said shroud into engagement with said shroud-receiving portion. 
   
   
     8. A fastener in accordance with  claim 1  wherein said thickened wall portion is provided by tapering an inner sidewall of said shroud. 
   
   
     9. A fastener in accordance with  claim 8  wherein said shroud-receiving portion of said fastener body is correspondingly tapered to accommodate said shroud. 
   
   
     10. A fastener in accordance with  claim 1  wherein said fastener is one of a closed-end locking wheel nut, an open-end locking wheel nut and a locking wheel bolt. 
   
   
     11. A high security fastener, comprising:
 a fastener body; 
 a first body end on said fastener body; 
 a key-receiving pattern at said first body end; 
 a second body end on said fastener body; 
 a thread pattern extending from said second body end; 
 a shroud-receiving body portion on said fastener body extending from said first body end toward said second body ends; 
 a shroud concentrically mounted on said shroud receiving portion, said shroud having first and second annular faces, said second annular face being an interior annular face; 
 an annular clearance groove in said shroud-receiving body portion at one end of said shroud that is remote from said first body end; 
 said shroud having a thickened wall portion proximate to said first body end to resist insertion of an unauthorized tool between said shroud and said body; 
 a first shroud-retaining member on said fastener body adapted to engage said shroud first annular face and restrain said shroud in a direction of movement toward said second body end; 
 a second shroud-retaining member on said fastener body adapted to engage said shroud interior annular face and restrain said shroud in a direction of movement toward said first body end; 
 said second retaining member retaining said shroud by engaging said shroud interior annular face and being seated in an annular retainer groove on said shroud-receiving portion that is spaced from said first body end; and 
 said shroud being supported in rotatable relationship with said shroud-receiving portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener rotating when said fastener is engaged with an external structure at a design installation torque. 
 
   
   
     12. A fastener in accordance with  claim 11  wherein said first shroud-retaining member comprises a shoulder integrally formed on said fastener body that faces toward said first body end, and said second shroud-retaining member comprises a retaining clip. 
   
   
     13. A high security fastener, comprising:
 a fastener body; 
 a first body end on said fastener body; 
 a key-receiving pattern at said first body end; 
 a second body end on said fastener body; 
 a thread pattern extending from said second body end; 
 a shroud-receiving body portion on said fastener body extending from said first body end toward said second body ends; 
 a shroud concentrically mounted on said shroud receiving portion, said shroud having a first annular end face and a second interior annular face; 
 said shroud having a thickened wall portion proximate to said first body end to resist insertion of an unauthorized tool between said shroud and said body; 
 first shroud retaining means for retaining said shroud in facing relationship with said shroud first annular face to restrain said shroud in a direction of movement toward said second body end; 
 said first shroud retaining means engaging said shroud first annular end face; 
 second shroud retaining means formed as a discrete retaining ring mounted on said fastener body for retaining said shroud in facing relationship with said shroud second annular face to restrain said shroud in a direction of movement toward said first body end; 
 said retaining ring retaining said shroud by engaging said shroud second annular face and being seated in an annular retainer groove on said shroud-receiving portion that is disposed closer to said second body end than said first body end; and 
 said first and second shroud retaining means supporting said shroud in rotatable relationship with said shroud-receiving portion such that said shroud will rotate relative to said fastener body under an applied external torque prior to said fastener rotating when said fastener is engaged with an external structure at a design installation torque. 
 
   
   
     14. A fastener in accordance with  claim 13  wherein said first shroud retaining means comprises a shoulder integrally formed on said fastener body and facing toward said first body end, and said second shroud retaining means comprises a split ring member.